Why doorway pages are used?

I heard that doorway pages are very useful to get ranking in less time. Is that true? Should I use them? Please guide me.

Doorway pages are a group of low quality pages which is developed to promote a particular keyword and which have no relevant content or may have duplicate content. These low quality pages will redirect you to a different page of a website which the webmaster feel is the most important. It is a black hat seo technique.

First of all, I want to tell you Doorway pages is a kind of black hat technique, it should not be done in order to rank your website keywords on search engine result. Doorway pages mean the backlinks have no relevancy with its web page content for an example the anchor text is "SEO service" and the landing page is web designing page thus, it is counted in a black hat technique.

If you know please tell me

hello...Design elements and videos are generally missing and graphics, if at all, are used to accommodate keywords in alt text. ... They have no added value much like overly optimized keyword pages. Doorway pages are typically highly optimized to rank well on search engines.

Doorway pages can be helpful for website owners in order to make a connection to the target page. Since doorway pages are usually used to achieve a higher rank in search engines for the selected keywords, those pages usually consists of plain HTML code and have a simple design.

Hi............!
Doorway pages can be helpful for website owners in order to make a connection to the target page. ... Since doorway pages are usually used to achieve a higher rank in search engines for the selected keywords, those pages usually consists of plain HTML code and have a simple design.
Thanks....

Doorway pages are loaded with large amounts of text and are usually visually quite poor. Design elements and videos are generally missing and graphics, if at all, are used to accommodate keywords in alt text. Elements such as Flash or JavaScript that cannot be read easily by Google are not included.

Why are you asking this? Are you planning some black hat techniques?

Doorway pages are the low-quality pages which are optimized to rank well for specific keywords and they act as a door between user and content.

Creating doorway pages is one of the Black Hat techniques which should NOT be used